This invention is directed to a radio frequency (RF) choke and, in particular to a choke for separating an AC power signal from a broadband signal when both are carried together on a coaxial line.
It is common practice in the cable distribution system to utilize a broadband RF signal in the 50 to 1000 MHz range to carry a number of television channels and other information to a subscriber location and an RF signal in the 5 to 40 MHz range to carry information from the subscriber to the system distributor. An AC power signal in the 50–60 Hz is also transmitted along with the RF signal upon the same coaxial cable to provide power to system amplifiers and the like.
In CATV and telecommunication systems, RF chokes are employed for separating AC power signals from the RF signals at various locations along the cable system, so that the separated RF signal can be processed individually by RF devices such as couplers, splitters and the like. The RF chokes generally used to isolate the RF devices from the AC power signals by shunting high current AC power signals, typically in the 8 to 12 ampere range, around the RF devices. The RF choke are designed to pass the 8–12 ampere flow, and these high currents can produce hum modulations which will degrade the RF signal quality.